How the Railway is Signalled

The railway comprises a single line with two termini. It operates a version of traditional One Engine in Steam (OES) signalling regulations. No train may occupy the single line unless its driver has what we call the token (which is a bit like a giant engraved key) as his authority.

Thame Junction, the remote terminus just outside Princes Risborough, comprises a simple run-round loop and a single siding. Connections are worked from a ground frame of levers which is normally locked but can be released by the token. Train movements here are controlled by a combination of Stop boards and handsignals.

The other terminus, at Chinnor, is more complex. The points and signals are worked by levers in a 120 year old signal cabin (re-located to Chinnor in 2007) which is still being developed.

Though limiting, the token released ground frame provided a simple system which served the railway well through its formative years. The chief limitation was that nothing could move at Chinnor station while a train was out on the single line with the token, so we could not shunt or prepare the next train until the first got back. This is why we commissioned the new Chinnor signal box and signals, and we now have both greater safety and more flexibility as a result. Visitors appreciate the railway atmosphere created by the signals and box too; it beats a man with a flag!

We still have one key operating restriction: we cannot run a loco around a train at Chinnor with the passengers still on board, as the Loop is beyond the end of the currently authorised passenger running line. We have to top and tail dining trains etc, so we can reverse them without throwing passengers out in the rain between meal courses! We aim to relocate one set of points and add two more signals and their associated controls and then with the upgrading of track etc., to remove this restriction.

Signals at Chinnor are mechanically operated semaphore and disc signals as once used on the Great Western Railway and the Western Region of British Railways. Equipment was rescued some years ago, and has been restored and installed by members of our Signal and Telegraph Department.

The foot crossing of the railway at Chinnor, which is used by visitors to access the station, has staff operated gates which are supervised from the signal box and interlocked with the signals.

The line has two intermediate vehicular crossings at Wainhill and Horsenden Lane are also operated by railway staff, and stand normally with their gates closed across the line. Depending on the timetable and the numbers of staff (all volunteers) available, the crossings may be worked by train crew or by a keeper based at the crossing. Each crossing is protected by Stop boards, and authority for trains to pass these is given by handsignal once the gates have been opened.

There are also several user-worked crossings. At these, it is the road or bridlepath user who is responsibility to make sure there are no trains coming, and then to work the gates so they can cross. Generally these are found on private roads giving access to a farm or between fields etc.

As the railway grows, and particularly with an extension into Princes Risborough in mind, we must prepare for it's future operating requirements. It is for this reason that the signalling systems at Chinnor are being developed.

All the work of relocating and erecting the signal box at Chinnor, restoring and refitting it, and of restoring and installing all of the signalling equipment beside the line has been funded by donations to a dedicated appeal. We still need funds in order to continue/complete the signalling works at Chinnor, and to be able to look after and improve the venerable signal box for the years to come.

If you would like to make a donation to this, or any other project on the railway from your credit or debit card, then please see our donations page.

Also, we are always short of working volunteers. If you would like to be a part of this project by joining the team please get in touch. You can use the feedback section of this website, or simply come and see us at Chinnor.